If you download an MSI package and look at its properties, you should see the actual changeset hashes that were used to build that particular package (look for the "Comments" property in the "Details" tab, which for example reads "Installs TortoiseHg 2.0.3+183-774d4419f199, Mercurial 1.8.2+139-98f79a5c3086 on x64"). Once installed, entering 'thg version' and/or 'hg version' on the command line will also tell you the exact tag or changeset hashes.

Building your own packages

To use thg-winbuild to build your own Mercurial or TortoiseHg packages or to simply build the THG docs, hg clone https://bitbucket.org/tortoisehg/thg-build to your Windows machine, cd into the winbuild subrepo and carefully follow the instructions in README.txt.